This invention relates to imidazoquinoline compounds that have ether and heterocycle or heteroaryl functionality at the 1-position, and to pharmaceutical compositions containing such compounds. A further aspect of this invention relates to the use of these compounds as immunomodulators, for inducing cytokine biosynthesis in animals, and in the treatment of diseases, including viral and neoplastic diseases.
The first reliable report on the 1H-imidazo[4,5-c]quinoline ring system. Backman et al., J. Org. Chem. 15, 1278-1284 (1950) describes the synthesis of 1-(6-methoxy-8-quinolinyl)-2-methyl-1H-imidazo[4,5-c]quinoline for possible use as an antimalarial agent. Subsequently, syntheses of various substituted 1H-imidazo[4,5-c]quinolines were reported. For example, Jain et al., J. Med. Chem. 11, pp. 87-92 (1968), synthesized the compound 1-[2-(4-piperidyl)ethyl]-1H-imidazo[4,5-c]quinoline as a possible anticonvulsant and cardiovascular agent. Also, Baranov et al., Chem. Abs. 85, 94362 (1976), have reported several 2-oxoimidazo[4,5-c]quinolines, and Berenyi et al., J. Heterocyclic Chem. 18, 1537-1540 (1981), have reported certain 2-oxoimidazo[4,5-c]quinolines.
Certain 1H-imidazo[4,5-c]quinolin-4-amines and 1- and 2-substituted derivatives thereof were later found to be useful as antiviral agents, bronchodilators and immunomodulators. These are described in, inter alia, U.S. Pat. Nos. 4,689,338; 4,698,348; 4,929,624; 5,037,986; 5,268,376; 5,346,905; and 5,389,640, all of which are incorporated herein by reference.
There continues to be interest in the imidazoquinoline ring system. Certain 1H-imidazo[4,5-c]naphthyridine-4-amines, 1H-imidazo[4,5-c]pyridin-4-amines, and 1H-imidazo[4,5-c]quinolin-4-amines having an ether containing substituent at the 1 position are known. These are described in U.S. Pat. Nos. 5,268,376; 5,389,640; 5,494,916; and WO 99/29693.
There is a continuing need for compounds that have the ability to modulate the immune response, by induction of cytokine biosynthesis or other mechanisms.
We have found a new class of compounds that are useful in inducing cytokine biosynthesis in animals. Accordingly, this invention provides imidazo[4,5-c]quinoline-4-amine and tetrahydroimidazo[4,5-c]quinoline-4-amine compounds that have an ether containing substituent at the 1-position. The compounds are described by Formulas (I), (II), (III) and (IV), which are defined in more detail infra. These compounds share the general structural formula 
wherein X, R1, R2, and R are as defined herein for each class of compounds having Formulas (I), (II), (III) and (IV).
The compounds of Formulas (I), (II), (III), and (IV) are useful as immune response modifiers due to their ability to induce cytokine biosynthesis and otherwise modulate the immune response when administered to animals. This makes the compounds useful in the treatment of a variety of conditions such as viral diseases and tumors that are responsive to such changes in the immune response.
The invention further provides pharmaceutical compositions containing the immune response modifying compounds, and methods of inducing cytokine biosynthesis in an animal, treating a viral infection in an animal, and/or treating a neoplastic disease in an animal by administering a compound of Formula (I), (II), (III), or (IV) to the animal.
In addition, the invention provides methods of synthesizing the compounds of the invention and intermediates useful in the synthesis of these compounds.
As mentioned earlier, we have found certain compounds that induce cytokine biosynthesis and modify the immune response in animals. Such compounds are represented by Formulas (I), (II), (III), and (IV), as shown below.
Imidazoquinoline compounds of the invention, which have ether and heterocyclyl or heteroaryl functionality at the 1-position are represented by Formula (I): 
wherein:
X is xe2x80x94CHR3xe2x80x94, xe2x80x94CHR3-alkyl-, or xe2x80x94CHR3-alkenyl-;
R1 is selected from the group consisting of:
-heteroaryl;
-heterocyclyl;
xe2x80x94R4-heteroaryl; and
xe2x80x94R4-heterocyclyl;
R2 is selected from the group consisting of:
-hydrogen;
-alkyl;
-alkenyl;
-aryl;
-heteroaryl;
-heterocyclyl;
-alkyl-Y-alkyl;
-alkyl-Y-alkenyl;
-alkyl-Y-aryl; and
-alkyl or alkenyl substituted by one or more substituents selected from the group consisting of:
xe2x80x94OH;
-halogen;
xe2x80x94N(R3)2;
xe2x80x94COxe2x80x94N(R3)2;
xe2x80x94COxe2x80x94C1-10 alkyl;
xe2x80x94COxe2x80x94Oxe2x80x94C1-10 alkyl;
xe2x80x94N3;
-aryl;
-heteroaryl;
-heterocyclyl;
xe2x80x94CO-aryl; and
xe2x80x94CO-heteroaryl;
R4 is alkyl or alkenyl, which may be interrupted by one or more xe2x80x94Oxe2x80x94 groups;
each R3 is independently H or C1-10 alkyl;
each Y is independently xe2x80x94Oxe2x80x94 or xe2x80x94S(O)O0-2xe2x80x94;
n is 0 to 4; and
each R present is independently selected from the group consisting of C1-10 alkyl, C1-10 alkoxy, hydroxy, halogen and trifluoromethyl;
or a pharmaceutically acceptable salt thereof.
The invention also provides imidazoquinoline compounds that contain ether functionality at the 1-position, where the ether containing substituent also contains an alkynyl group and a heterocyclyl or heteroaryl group. These compounds are represented by Formula (II): 
wherein:
X is xe2x80x94CHR3xe2x80x94, xe2x80x94CHR3-alkyl-, or xe2x80x94CHR3-alkenyl-;
R10 is selected from the group consisting of heteroaryl and heterocyclyl;
R2 is selected from the group consisting of:
-hydrogen;
-alkyl;
-alkenyl;
-aryl;
-heteroaryl;
-heterocyclyl;
-alkyl-Y-alkyl;
-alkyl-Y-alkenyl;
-alkyl-Y-aryl; and
-alkyl or alkenyl substituted by one or more substituents selected from the group consisting of:
xe2x80x94OH;
-halogen;
xe2x80x94N(R3)2;
xe2x80x94COxe2x80x94N(R3)2;
xe2x80x94COxe2x80x94C1-10 alkyl;
xe2x80x94COxe2x80x94Oxe2x80x94C1-10 alkyl;
xe2x80x94N3;
-aryl;
-heteroaryl;
-heterocyclyl;
xe2x80x94CO-aryl; and
xe2x80x94CO-heteroaryl;
n is 0 to 4;
each R3 is independently H or C1-10 alkyl;
each Y is independently xe2x80x94Oxe2x80x94 or xe2x80x94S(O)0-2xe2x80x94; and
each R present is independently selected from the group consisting of C1-10 alkyl, C1-10 alkoxy, hydroxy, halogen and trifluoromethyl;
or a pharmaceutically acceptable salt thereof.
The invention also includes tetrahydroimidazoquinoline compounds that bear an ether and heterocyclyl or heteroaryl containing substituent at the 1-position. Such tetrahydroimidazoquinoline compounds are represented by Formula (III): 
wherein:
X is xe2x80x94CHR3xe2x80x94, xe2x80x94CHR3-alkyl-, or xe2x80x94CHR3-alkenyl-;
R1 is selected from the group consisting of:
-heteroaryl;
-heterocyclyl;
xe2x80x94R4-heteroaryl; and
xe2x80x94R4-heterocyclyl;
R2 is selected from the group consisting of:
-hydrogen;
-alkyl;
-alkenyl;
-aryl;
-heteroaryl;
-heterocyclyl;
-alkyl-Y-alkyl;
-alkyl-Y-alkenyl;
-alkyl-Y-aryl; and
-alkyl or alkenyl substituted by one or more substituents selected from the group consisting of:
xe2x80x94OH;
-halogen;
xe2x80x94N(R3)2;
xe2x80x94COxe2x80x94N(R3)2;
xe2x80x94COxe2x80x94C1-10 alkyl;
xe2x80x94COxe2x80x94Oxe2x80x94C1-10 alkyl;
xe2x80x94N3;
-aryl;
-heteroaryl;
-heterocyclyl;
xe2x80x94CO-aryl; and
xe2x80x94CO-heteroaryl;
R4 is alkyl or alkenyl, which may be interrupted by one or more xe2x80x94Oxe2x80x94 groups;
each R3 is independently H or C1-10 alkyl;
each Y is independently xe2x80x94Oxe2x80x94 or xe2x80x94S(O)0-2xe2x80x94;
n is 0 to 4; and
each R present is independently selected from the group consisting of C1-10 alkyl, C1-10 alkoxy, hydroxy, halogen and trifluoromethyl;
or a pharmaceutically acceptable salt thereof.
An additional class of immune response modifying compounds of the invention are tetrahydroimidazoquinoline compounds that have an ether containing substituent at the 1-position, where the ether containing substituent also contains an alkynyl group and a heterocyclyl or heteroaryl group. These compounds are represented by Formula (IV): 
wherein:
X is xe2x80x94CHR3xe2x80x94, xe2x80x94CHR3-alkyl-, or xe2x80x94CHR3-alkenyl-;
R10 is selected from the group consisting of heteroaryl and heterocyclyl;
R2 is selected from the group consisting of:
-hydrogen;
-alkyl;
-alkenyl;
-aryl;
-heteroaryl;
-heterocyclyl;
-alkyl-Y-alkyl;
-alkyl-Y-alkenyl;
-alkyl-Y-aryl; and
-alkyl or alkenyl substituted by one or more substituents selected from the group, consisting of:
xe2x80x94OH;
-halogen;
xe2x80x94N(R3)2;
xe2x80x94COxe2x80x94N(R3)2;
xe2x80x94COxe2x80x94C1-10 alkyl;
xe2x80x94COxe2x80x94Oxe2x80x94C1-10 alkyl;
xe2x80x94N3;
-aryl;
-heteroaryl;
-heterocyclyl;
xe2x80x94CO-aryl; and
xe2x80x94CO-heteroaryl;
each R3 is independently H or C1-10 alkyl;
each Y is independently xe2x80x94Oxe2x80x94 or xe2x80x94S(O)0-2xe2x80x94;
n is 0 to 4; and
each R present is independently selected from the group consisting of C1-10 alkyl, C1-10 alkoxy, hydroxy, halogen and trifluoromethyl;
or a pharmaceutically acceptable salt thereof.
Preparation of the Compounds
Compounds of the invention can be prepared according to Reaction Scheme I where R, R2, X and n are as defined above and R11 is alkyl substituted by a heteroaryl group wherein the heteroaryl group may be unsubstituted or may be substituted as defined infra or R11 is substituted heteroaryl as defined infra with the proviso that if R11 is substituted heteroaryl at least one substituent is a strong electron withdrawing group located ortho or para to the ether bond.
In Reaction Scheme I a 4-amino-1H-imidazo[4,5-c]quinolin-1-yl alcohol of Formula X is alkylated with a halide of Formula XI to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XII which is a subgenus of Formula I. The alcohol of Formula X is reacted with sodium hydride in a suitable solvent such as N,N-dimethylformamide to form an alkoxide. The halide is then added to the reaction mixture. The reaction can be carried out at ambient temperature or with gentle heating (xcx9c50xc2x0 C.) if desired. The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods.
Many compounds of Formula X are known, see for example Gerster, U.S. Pat. No. 4,689,338 and Gerster et. al., U.S. Pat. No. 5,605,899, the disclosures of which are incorporated by reference herein; others can readily be prepared using known synthetic routes, see for example, Andre et. al, U.S. Pat. No. 5,578,727; Gerster, U.S. Pat. No. 5,175,296; Nikolaides et al., U.S. Pat. No. 5,395,937; and Gerster et. al., U.S. Pat. No. 5,741,908, the disclosures of which are incorporated by reference herein. Many halides of Formula XI are commercially available; others can be readily prepared using known synthetic methods. 
Compounds of the invention can also be prepared according to Reaction Scheme II where R, R2, R11, X and n are as defined above.
In step (1) of Reaction Scheme II the hydroxy group of a 1H-imidazo[4,5-c]quinolin-1-yl alcohol of Formula XIII is protected with a benzyl group. The alcohol of Formula XIII is reacted with sodium hydride in a suitable solvent such as N,N-dimethylformamide to form an alkoxide. The alkoxide is then alkylated with benzyl bromide to provide a compound of Formula XIV. The reaction can be carried out at ambient temperature. Many compounds of Formula XIII are known, see for example, Gerster, U.S. Pat. No. 4,689,338; others can readily be prepared using known synthetic routes, see for example, Gerster et al., U.S. Pat. No. 5,605,899 and Gerster, U.S. Pat. No. 5,175,296.
In step (2) of Reaction Scheme II a compound of Formula XIV is oxidized to provide a 1H-imidazo[4,5-c]quinoline-5N-oxide of Formula XV using a conventional oxidizing agent capable of forming N-oxides. Preferably a solution of a compound of Formula XIV in a suitable solvent such as chloroform or dichloromethane is oxidized using 3-chloroperoxybenzoic acid at ambient temperature.
In step (3) of Reaction Scheme II a 1H-imidazo[4,5-c]quinoline-5N-oxide of Formula XV is chlorinated to provide a 4-chloro-1H-imidazo[4,5-c]quinoline of Formula XVI. Preferably a solution of a compound of Formula XV in a suitable solvent such as toluene is treated with phosphorous oxychloride at ambient temperature.
In step (4) of Reaction Scheme II a 4-chloro-1H-imidazo[4,5-c]quinoline of Formula XVI is reacted with phenol to provide a 4-phenoxy-1H-imidazo[4,5-c]quinoline of Formula XVII. The phenol is reacted with sodium hydride in a suitable solvent such as diglyme to form a phenoxide. The phenoxide is then reacted at an elevated temperature with a compound of Formula XVI.
In step (5) of Reaction Scheme II the benzyl protecting group is removed from a compound of Formula XVII to provide a 4-phenoxy-1H-imidazo[4,5-c]quinolin-1-yl alcohol of Formula XVIII. The reaction is preferably carried out by adding triflic acid in a controlled fashion to a solution of a compound of Formula XVII in a suitable solvent such as dichloromethane at ambient temperature.
In step (6) of Reaction Scheme II a 4-phenoxy-1H-imidazo[4,5-c]quinolin-1-yl alcohol of Formula XVIII is alkylated with halide Hal-R11 to provide a 4-phenoxy-1H-imidazo[4,5-c]quinolin-1-yl ether of Formula XIX. The alkoxide of a compound of Formula XVIII is formed by adding the alcohol to a biphasic mixture of aqueous 50% sodium hydroxide and an inert solvent such as dichloromethane in the presence of a phase transfer catalyst such as benzyltrimethlammonium chloride. The alkoxide is then alkylated. The reaction can be carried out at ambient temperature.
In step (7) of Reaction Scheme II a 4-phenoxy-1H-imidazo[4,5-c]quinolin-1-yl ether of Formula XIX is aminated to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XII which is a subgenus of Formula I. The reaction can be carried out by combining a compound of Formula XIX with ammonium acetate and heating the resulting mixture at xcx9c150xc2x0 C. The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods. 
Tetrahydroimidazoquinolines of the invention can be prepared according to Reaction Scheme III where R, R2, R11, X and n are as defined above.
In Reaction Scheme III a 4-amino-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-1-yl alcohol of Formula XX is alkylated with a halide of Formula XI to provide a 6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amine of Formula XXI which is a subgenus of Formula III. The alcohol of Formula XX is reacted with sodium hydride in a suitable solvent such as N,N-dimethylformamide to form an alkoxide. The alkoxide is then combined with the halide. The reaction can be carried out at ambient temperature. The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods.
Many tetrahydro-1H-imidazo[4,5-c]quinolines of Formula XX are known, see for example, Nikolaides et al., U.S. Pat. No. 5,352,784; others can be prepared using known synthetic methods, see for example, Lindstrom, U.S. Pat. No. 5,693,811; the disclosures of which are incorporated by reference herein. 
Compounds of the invention can be prepared according to Reaction Scheme IV where R, R2, X and n are as defined above and R12 is a heteroaryl group which may be unsubstituted or substituted as defined infra.
In step (1) of Reaction Scheme IV a 1H-imidazo[4,5-c]quinolin-1-yl alcohol of Formula XIII is alkylated with a halide of Formula XXII to provide a 1H-imidazo[4,5-c]quinolin-1-yl ether of Formula XXIII. The compound of Formula XIII and the halide of Formula XXII are combined in a biphasic mixture of 50% aqueous sodium hydroxide and a suitable solvent such as dichloromethane in the presence of a phase transfer catalyst such as benzyltrimethylammonium chloride. The reaction can be run at ambient temperature.
In step (2) of Reaction Scheme IV a 1H-imidazo[4,5-c]quinoline of Formula XXIII is oxidized using the method of step (2) of Reaction Scheme II to provide a 1H-imidazo[4,5-c]quinoline-5N-oxide of Formula XXIV.
In step (3) of Reaction Scheme IV a 1H-imidazo[4,5-c]quinoline-5N-oxide of Formula XXIV is reacted with trichloroacetyl isocyanate to provide a 1H-imidazo[4,5-c]quinolin-4-yl acetamide of Formula XXV. Preferably the isocyanate is added in a controlled fashion at ambient temperature to a solution of the 5N-oxide in a suitable solvent such as dichloromethane.
In step (4) of Reaction Scheme IV a 1H-imidazo[4,5-c]quinolin-4-yl acetamide of Formula XXV is hydrolyzed to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXVI. The hydrolysis can be carried out by conventional methods preferably by treating a solution of a compound of Formula XXV in methanol with sodium methoxide.
In step (5) of Reaction Scheme IV 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXVI is coupled with a halide of formula Hal-R12 using a transition metal catalyst to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXVII which is a subgenus of Formula II. Preferably a compound of Formula XXVI is combined with the halide in the presence of copper (I) iodide, dichlorobis(triphenylphosphine)palladium(II), and excess triethylamine in a suitable solvent such as N,N-dimethylformamide or acetonitrile. The reaction is preferably carried out at an elevated temperature (60-80xc2x0 C.). The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods. 
Compounds of the invention can be prepared according to Reaction Scheme V where R, R2, R12, X and n are as defined above and BOC is tert-butoxycarbonyl.
In step (1) of Reaction Scheme V the amino group of a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXVI is protected with tert-butoxycarbonyl groups. A compound of Formula XXVI is combined with di-tert-butyl dicarbonate in a suitable solvent such as N,N-dimethylformamide in the presence of 4-(dimethylamino)pyridine and triethylamine. The reaction is carried out at an elevated temperature (80-85xc2x0 C.).
In step (2) of Reaction Scheme V a protected 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXVIII is coupled with a halide of formula Hal-R12 using a transition metal catalyst to provide a protected 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXIX. Preferably a compound of Formula XXVIII is combined with the halide in the presence of copper (I) iodide, dichlorobis(triphenylphosphine)palladium(II), and excess triethylamine in a suitable solvent such as N,N-dimethylformamide or acetonitrile. The reaction can be carried out at ambient temperature or at an elevated temperature (40-80xc2x0 C.).
In step (3) of Reaction Scheme V the protecting groups are removed by hydrolysis under acidic conditions to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXVII which is a subgenus of Formula II. Preferably a compound of Formula XXIX is treated with trifluoroacetic acid in a suitable solvent such as dichloromethane. The reaction can be run at ambient temperature or at a reduced temperature (0xc2x0 C.). The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods.
In step (4) of Reaction Scheme V the alkyne bond of a protected 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXIX is reduced to provide a protected 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXX. Preferably, the reduction is carried out using a conventional heterogeneous hydrogentation catalyst such as platinum oxide, platinum on carbon or palladium on carbon. The reaction can conveniently be carried out on a Parr apparatus in a suitable solvent such as methanol.
In step (5) of Reaction Scheme V the protecting groups of a compound of Formula XXX are removed in the same manner as in step (3) to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXXI which is a subgenus of Formula I. The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods. 
Compounds of the invention can be prepared according to Reaction Scheme VI where R, R2, R12, X and n are as defined above and CBZ is benzyloxycarbonyl.
In step (1) of Reaction Scheme VI the amino group of a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXVI is protected with benzyloxycarbonyl groups. A compound of Formula XXVI is combined with dibenzyl dicarbonate in a suitable solvent such as N,N-dimethylformamide. The reaction can be carried out at ambient temperature or with mild heating (40xc2x0 C.).
In step (2) of Reaction Scheme VI a protected 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXXII is coupled with a halide of formula Hal-R12 using a transition metal catalyst to provide a protected 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXXIII. Preferably a compound of Formula XXXII is combined with the halide in the presence of copper (I) iodide, dichlorobis(triphenylphosphine)palladium(II), and excess triethylamine in a suitable solvent such as N,N-dimethylformamide or acetonitrile. The reaction can be carried out at ambient temperature or at an elevated temperature (40-80xc2x0 C.).
In step (3) of Reaction Scheme VI the protecting groups are removed by hydrolysis to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXVII which is a subgenus of Formula II. Preferably a compound of Formula XXXIII is treated with sodium methoxide in a suitable solvent such as methanol. The reaction can be run at ambient temperature. The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods.
In step (4) of Reaction Scheme VI the protecting groups of a compound of Formula XXXIII are removed by hydrogenolysis and the alkyne bond is reduced to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXXI which is a subgenus of Formula I. Preferably, the hydrogenolysis/reduction is carried out using palladium hydroxide on carbon. The reaction can conveniently be carried out on a Parr apparatus in a suitable solvent such as methanol. The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods. 
Compounds of the invention can be prepared according to Reaction Scheme VII where R, R1, R2, X and n are as defined above.
In step (1) of Reaction Scheme VII a 2,4-dichloro-3-nitroquinoline of Formula XXXIV is reacted with an amine of Formula R1xe2x80x94Oxe2x80x94Xxe2x80x94NH2 to provide a 2-chloro-3-nitroquinolin-4-amine of Formula XXXV. The reaction can be carried out by adding the amine to a solution of a compound of Formula XXXIV in a suitable solvent such as chloroform or dichloromethane and optionally heating. Many quinolines of Formula XXXIV are known or can be prepared using known synthetic methods (see for example, Andre et al., U.S. Pat. No. 4,988,815 and references cited therein).
In step (2) of Reaction Scheme VII a 2-chloro-3-nitroquinolin-4-amine of Formula XXXV is reduced to provide a 2-chloroquinoline-3,4-diamine of Formula XXXVI. Preferably, the reduction is carried out using a conventional heterogeneous hydrogenation catalyst such as platinum on carbon or palladium on carbon. The reaction can conveniently be carried out on a Parr apparatus in a suitable solvent such as isopropyl alcohol or toluene.
In step (3) of Reaction Scheme VII a 2-chloroquinoline-3,4-diamine of Formula XXXVI is is reacted with a carboxylic acid or an equivalent thereof to provide a 4-chloro-1H-imidazo[4,5-c]quinoline of Formula XXXVII. Suitable equivalents to carboxylic acid include orthoesters, and 1,1-dialkoxyalkyl alkanoates. The carboxylic acid or equivalent is selected such that it will provide the desired R2 substituent in a compound of Formula XXXVII. For example, triethyl orthoformate will provide a compound where R2 is hydrogen and triethyl orthoacetate will provide a compound where R2 is methyl. The reaction can be run in the absence of solvent or in an inert solvent such as toluene. The reaction is run with sufficient heating to drive off any alcohol or water formed as a byproduct of the reaction. Optionally a catalyst such as pyridine hydrochloride can be included.
Alternatively, step (3) can be carried out by (i) reacting the diamine of Formula XXXVI with an acyl halide of Formula R2C(O)Cl and then (ii) cyclizing. In part (i) the acyl halide is added to a solution of the diamine in an inert solvent such as acetonitrile, pyridine or dichloromethane. The reaction can be carried out at ambient temperature. In part (ii) the product of part (i) is heated in an alcoholic solvent in the presence of a base. Preferably the product of part (i) is refluxed in ethanol in the presence of an excess of triethylamine or heated with methanolic ammonia. Alternatively, if step (i) has been run in pyridine, step (ii) can be carried out by heating the reaction mixture after analysis indicates that step (i) is complete.
In step (4) of Reaction Scheme VII a 4-chloro-1H-imidazo[4,5-c]quinoline of Formula XXXVII is aminated to provide a 1H-imidazo[4,5-c]quinolin4-amine of Formula I. The reaction is carried out by heating (e.g.,125-175xc2x0 C.) a compound of Formula XXXVII under pressure in a sealed reactor in the presence of a solution of ammonia in an alkanol. The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods. 
Compounds of the invention can be prepared according to Reaction Scheme VIII where R, R1, R2, X and n are as defined above.
In Reaction Scheme VIII a 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXXVIII is alkylated with a halide of Formula XXXIX to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula I. The compound of Formula XXXVIII is reacted with sodium hydride in a suitable solvent such as N,N-dimethylformamide. The halide is then added to the reaction mixture. The reaction can be carried out at an elevated temperature (xcx9c100xc2x0 C.). Alkylation occurs at both the N1 and the N3 nitrogens; however, the desired 1-isomer can be readily separated from the 3-isomer using conventional techniques such as column chromatography and recrystallization.
Many 1H-imidazo[4,5-c]quinolin-4-amines of Formula XXXVIII are known; others may be prepared using known synthetic methods, see for example, Gerster, U.S. Pat. No. 5,756,747 and the references cited therein. 
Compounds of the invention can be prepared according to Reaction Scheme IX where R, R1 R2, X and n are as defined above.
In step (1) of Reaction Scheme IX a 4-nitrotetrazolo[1,5-a]quinolin-5-ol of Formula XL is chlorinated to provide a 5-chloro-4-nitrotetrazolo[1,5-a]quinoline of Formula XLI. Conventional chlorinating agents can be used. Preferably the reaction is carried out using phosphorus oxychloride in a suitable solvent such as N,N-dimethylformamide. 4-Nitrotetrazolo[1,5-a]quinolin-5-ols of Formula XL are known or can be prepared using known synthetic methods (see for example, Gerster, et al., U.S. Pat. No. 5,741,908 and references cited therein).
In step (2) of Reaction Scheme IX a 5-chloro-4-nitrotetrazolo[1,5-a]quinoline of Formula XLI is reacted with an amine of Formula R1xe2x80x94Oxe2x80x94Xxe2x80x94NH2 to provide a 4-nitrotetrazolo[1,5-a]quinolin-5-amine of Formula XLII. The reaction can be carried out by adding the amine to a solution of a compound of Formula XLI in a suitable solvent such as dichloromethane in the presence of triethylamine.
In step (3) of Reaction Scheme IX a 4-nitrotetrazolo[1,5-a]quinolin-5-amine of Formula XLII is reduced using the method of step (2) in Reaction Scheme VII to provide a tetrazolo[1,5-a]quinolin-4,5-diamine of Formula XLIII.
In step (4) of Reaction Scheme IX a tetrazolo[1,5-a]quinolin-4,5-diamine of Formula XLIII is cyclized using the method of step (3) in Reaction Scheme VII to provide a 6H-imidazo[4,5-c]tetrazolo[1,5-a]quinoline of Formula XLIV.
In step (5) of Reaction Scheme IX a 6H-imidazo[4,5-c]tetrazolo[1,5-a]quinoline of Formula XLIV is reduced to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula I. Step (5) involves (i) reacting a compound of Formula XLIV with triphenylphosphine and then (ii) hydrolyzing. Part (i) can be carried out by combining a compound of Formula XLIV with triphenylphosphine in a suitable solvent such as 1,2-dichlorobenzene and heating. Part (ii) involves hydrolysis of the product from part (i). The hydrolysis can be carried out by conventional methods such as heating in the presence of water or a lower alkanol optionally in the presence of a catalyst such as an alkali metal hydroxide or lower alkoxide. The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods. 
Tetrahydroimidazoquinolines of the invention can be prepared according to Reaction Scheme X where R, R2, R12, X and n are as defined above.
In step (1) of Reaction Scheme X a 4-amino-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-1-yl alcohol of Formula XX is alkylated using the method of Reaction Scheme III with a halide of formula Hal-(CH2)1-10xe2x80x94CHxe2x89xa1CH to provide a 6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amine of Formula XLV.
In step (2) of Reaction Scheme X a 6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amine of Formula XLV is coupled using the method of step (5) of Reaction Scheme IV with a halide of Formula Hal-R12 to provide a 6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amine of Formula XLIV which is a subgenus of Formula IV. The product or a pharmaceutically acceptable salt thereof can be isolated using conventional methods. 
Compounds of the invention can be prepared according to Reaction Scheme XI where R, R1, R2, X and n are as defined above.
In step (1) of Reaction Scheme XI a 2,4-dihydroxy-3-nitro-6,7,8,9-tetrayhydroquinoline of Formula XLVII is chlorinated to provide a 2,4-dichloro-3-nitro-6,7,8,9-tetrayhydroquinoline of Formula XLVIII. Conventional chlorinating agents can be used. Preferably the reaction is carried out by combining a compound of Formula XLVII with phosphorous oxychloride and then heating (55-65xc2x0 C.). Compounds of Formula XLVII are known or can be prepared using known synthetic methods (see for example Nikolaides et al,. U.S. Pat. No. 5,352,784 and references cited therein).
In step (2) of Reaction Scheme XI a 2,4-dichloro-3-nitro-6,7,8,9-tetrayhydroquinoline of Formula XLVIII is reacted with an amine of Formula R1xe2x80x94Oxe2x80x94Xxe2x80x94NH2 to provide a 2-chloro-3-nitro-6,7,8,9-tetrahydroquinolin-4-amine of Formula XLIX. The reaction can be carried out by adding the amine to a solution of a compound of Formula XLVIII in a suitable solvent such as N,N-dimethylformamide and heating (55-65xc2x0 C.).
In step (3) of Reaction Scheme XI a 2-chloro-3-nitro-6,7,8,9-tetrahydroquinolin-4-amine of Formula XLIX is reacted with phenol using the method of step (4) of Reaction Scheme II to provide a 2-phenoxy-3-nitro-6,7,8,9-tetrahydroquinolin-4-amine of Formula L.
In step (4) of Reaction Scheme XI a 2-phenoxy-3-nitro-6,7,8,9-tetrahydroquinolin-4-amine of Formula L is reduced using the method of step (2) of Reaction Scheme VII to provide a 2-phenoxy-6,7,8,9-tetrahydroquinolin-3,4-diamine of Formula LI.
In step (5) of Reaction Scheme XI a 2-phenoxy-6,7,8,9-tetrahydroquinolin-3,4-diamine of Formula LI is cyclized using the method of step (3) of Reaction Scheme VII to provide a 4-phenoxy-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinoline of Formula LII.
In step (6) of Reaction Scheme XI a 4-phenoxy-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinoline of Formula LII is aminated using the method of step (7) of Reaction Scheme II to provide a 6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amine of Formula III. 
The invention also provides novel compounds useful as intermediates in the synthesis of the compounds of Formulas (I), (II), (III), and (IV). These intermediate compounds have the structural Formulas (V)-(IX) and (XLIV) described in more detail below.
One class of intermediate compounds has Formula (V): 
wherein:
X is xe2x80x94CHR3xe2x80x94, xe2x80x94CHR3-alkyl-, or xe2x80x94CHR3-alkenyl-;
R1 is selected from the group consisting of:
-heteroaryl;
-heterocyclyl;
xe2x80x94R4-heteroaryl;
xe2x80x94R4-heterocyclyl; and
xe2x80x94(CH2)1-10xe2x80x94Cxe2x89xa1Cxe2x80x94R10;
R2 is selected from the group consisting of:
-hydrogen;
-alkyl;
-alkenyl;
-aryl;
-heteroaryl;
-heterocyclyl;
-alkyl-Y-alkyl;
-alkyl-Y-alkenyl;
-alkyl-Y-aryl; and
-alkyl or alkenyl substituted by one or more substituents selected from the group consisting of:
xe2x80x94OH;
-halogen;
xe2x80x94N(R3)2;
xe2x80x94COxe2x80x94N(R3)2;
xe2x80x94COxe2x80x94C1-10 alkyl;
xe2x80x94COxe2x80x94Oxe2x80x94C1-10 alkyl;
xe2x80x94N3;
-aryl;
-heteroaryl;
-heterocyclyl;
xe2x80x94CO-aryl; and
xe2x80x94CO-heteroaryl;
R4 is alkyl or alkenyl, which may be interrupted by one or more xe2x80x94Oxe2x80x94 groups;
each R3 is independently H or C1-10 alkyl;
R10 is heteroaryl or heterocyclyl;
each Y is independently xe2x80x94Oxe2x80x94 or xe2x80x94S(O)0-2xe2x80x94;
n is 0 to 4; and
each R present is independently selected from the group consisting of C1-10 alkyl, C1-10 alkoxy, hydroxy, halogen and trifluoromethyl;
or a pharmaceutically acceptable salt thereof.
Another class of intermediates are imidazoquinoline-4-phenoxy compounds of Formula (VI): 
wherein:
X is xe2x80x94CHR3xe2x80x94, xe2x80x94CHR3-alkyl-, or xe2x80x94CHR3-alkenyl-;
R1 is selected from the group consisting of:
-heteroaryl;
-heterocyclyl;
xe2x80x94R4-heteroaryl;
xe2x80x94R4-heterocyclyl; and
xe2x80x94(CH2)1-10xe2x80x94Cxe2x89xa1Cxe2x80x94R10,
R2 is selected from the group consisting of:
-hydrogen;
-alkyl;
-alkenyl;
-aryl;
-heteroaryl;
-heterocyclyl;
-alkyl-Y-alkyl;
-alkyl-Y-alkenyl;
-alkyl-Y-aryl; and
-alkyl or alkenyl substituted by one or more substituents selected from the group consisting of:
xe2x80x94OH;
-halogen;
xe2x80x94N(R3)2;
xe2x80x94COxe2x80x94N(R3)2;
xe2x80x94COxe2x80x94C1-10 alkyl;
xe2x80x94COxe2x80x94Oxe2x80x94C1-10 alkyl;
xe2x80x94N3;
-aryl;
-heteroaryl;
-heterocyclyl;
xe2x80x94CO-aryl; and
xe2x80x94CO-heteroaryl;
R4 is alkyl or alkenyl, which may be interrupted by one or more xe2x80x94Oxe2x80x94 groups;
each R3 is independently H or C1-10 alkyl;
R10 is heteroaryl or heterocyclyl;
each Y is independently xe2x80x94Oxe2x80x94 or xe2x80x94S(O)0-2xe2x80x94;
n is 0 to 4; and
each R present is independently selected from the group consisting of C1-10 alkyl, C1-10 alkoxy, hydroxy, halogen and trifluoromethyl;
or a pharmaceutically acceptable salt thereof.
Another class of intermediate compounds is represented by Formula (VII): 
wherein:
Z is NH2 or NO2;
X is xe2x80x94CHR3xe2x80x94, xe2x80x94CHR3-alkyl-, or CHR3-alkenyl-;
R1 is selected from the group consisting of:
-heteroaryl;
-heterocyclyl;
xe2x80x94R4-heteroaryl; and
xe2x80x94R4-heterocyclyl;
R4 is alkyl or alkenyl, which may be interrupted by one or more xe2x80x94Oxe2x80x94 groups;
each R3 is independently H or C1-10 alkyl;
n is 0 to 4; and
each R present is independently selected from the group consisting of C1-10 alkyl, C1-10 alkoxy, hydroxy, halogen and trifluoromethyl;
or a pharmaceutically acceptable salt thereof.
Another class of intermediate compounds has the Formula (XLIV): 
wherein:
X is xe2x80x94CHR3xe2x80x94, xe2x80x94CHR3-alkyl-, or xe2x80x94CHR3-alkenyl-;
R1 is selected from the group consisting of:
-heteroaryl;
-heterocyclyl;
xe2x80x94R4-heteroaryl; and
xe2x80x94R4-heterocyclyl;
R2 is selected from the group consisting of:
-hydrogen;
-alkyl;
-alkenyl;
-aryl;
-heteroaryl;
-heterocyclyl;
-alkyl-Y-alkyl;
-alkyl-Y-alkenyl;
-alkyl-Y-aryl; and
-alkyl or alkenyl substituted by one or more substituents selected from the group consisting of:
xe2x80x94OH;
-halogen;
xe2x80x94N(R3)2;
xe2x80x94COxe2x80x94N(R3)2;
xe2x80x94COxe2x80x94C1-10 alkyl;
xe2x80x94COxe2x80x94Oxe2x80x94C1-10 alkyl;
xe2x80x94N3;
-aryl;
-heteroaryl;
-heterocyclyl;
xe2x80x94CO-aryl; and
xe2x80x94CO-heteroaryl;
R4 is alkyl or alkenyl, which may be interrupted by one or more xe2x80x94Oxe2x80x94 groups;
each R3 is independently H or C1-10 alkyl;
each Y is independently xe2x80x94Oxe2x80x94 or xe2x80x94S(O)0-2xe2x80x94;
n is 0 to 4; and
each R present is independently selected from the group consisting of C1-10 alkyl, C1-10 alkoxy, hydroxy, halogen and trifluoromethyl;
or a pharmaceutically acceptable salt thereof.
An additional class of intermediate compounds has the Formula (VIII): 
wherein:
X is xe2x80x94CHR3xe2x80x94, xe2x80x94CHR3-alkyl-, or xe2x80x94CHR3-alkenyl-;
R1 is selected from the group consisting of:
-heteroaryl;
-heterocyclyl;
xe2x80x94R4-heteroaryl; and
xe2x80x94R4-heterocyclyl;
R2 is selected from the group consisting of:
-hydrogen;
-alkyl;
-alkenyl;
-aryl;
-heteroaryl;
-heterocyclyl;
-alkyl-Y-alkyl;
-alkyl-Y-alkenyl;
-alkyl-Y-aryl; and
-alkyl or alkenyl substituted by one or more substituents selected from the group consisting of:
xe2x80x94OH;
-halogen;
xe2x80x94N(R3)2;
xe2x80x94COxe2x80x94N(R3)2;
xe2x80x94COxe2x80x94C1-10 alkyl;
xe2x80x94COxe2x80x94Oxe2x80x94C1-10 alkyl;
xe2x80x94N3;
-aryl;
-heteroaryl;
-heterocyclyl;
xe2x80x94CO-aryl; and
xe2x80x94CO-heteroaryl;
R4 is alkyl or alkenyl, which may be interrupted by one or more xe2x80x94Oxe2x80x94 groups;
each R3 is independently H or C1-10 alkyl;
each Y is independently xe2x80x94Oxe2x80x94 or xe2x80x94S(O)0-2xe2x80x94;
n is 0 to 4;
each R present is independently selected from the group consisting of C1-10 alkyl, C1-10 alkoxy, hydroxy, halogen and trifluoromethyl; and
R7 is tert-butyl or benzyl;
or a pharmaceutically acceptable salt thereof.
A further class of intermediates are imidazoquinoline-4-chloro compounds of the Formula (IX) 
wherein:
X is xe2x80x94CHR3xe2x80x94, xe2x80x94CHR3-alkyl-, or xe2x80x94CHR3-alkenyl-;
R1 is selected from the group consisting of:
-heteroaryl;
-heterocyclyl;
xe2x80x94R4-heteroaryl; and
xe2x80x94R4-heterocyclyl;
R2 is selected from the group consisting of:
-hydrogen;
-alkenyl;
-aryl;
-heteroaryl;
-heterocyclyl;
-alkyl-Y-alkyl;
-alkyl-Y-alkenyl;
-alkyl-Y-aryl; and
-alkyl or alkenyl substituted by one or more substituents selected from the group consisting of:
xe2x80x94OH;
-halogen;
xe2x80x94N(R3)2;
xe2x80x94COxe2x80x94N(R3)2;
xe2x80x94COxe2x80x94C1-10 alkyl;
xe2x80x94COxe2x80x94Oxe2x80x94C1-10 alkyl;
xe2x80x94N3;
-aryl;
-heteroaryl;
-heterocyclyl;
xe2x80x94CO-aryl; and
xe2x80x94CO-heteroaryl;
R4 is alkyl or alkenyl, which may be interrupted by one or more xe2x80x94Oxe2x80x94 groups;
each R3 is independently H or C1-10 alkyl;
each Y is independently xe2x80x94Oxe2x80x94 or xe2x80x94S(O)0-2xe2x80x94;
n is 0 to 4; and
each R present is independently selected from the group consisting of C1-10 alkyl, C1-10 alkoxy, hydroxy, halogen and trifluoromethyl;
or a pharmaceutically acceptable salt thereof.
As used herein, the terms xe2x80x9calkylxe2x80x9d, xe2x80x9calkenylxe2x80x9d and the prefix xe2x80x9calk-xe2x80x9d are inclusive of both straight chain and branched chain groups and of cyclic groups, i.e. cycloalkyl and cycloalkenyl. Unless otherwise specified, these groups contain from 1 to 20 carbon atoms, with alkenyl groups containing from 2 to 20 carbon atoms. Preferred groups have a total of up to 10 carbon atoms. Cyclic groups can be monocyclic or polycyclic and preferably have from 3 to 10 ring carbon atoms. Exemplary cyclic groups include cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, and adamantyl.
In addition, the alkyl and alkenyl portions of xe2x80x94Xxe2x80x94 groups can be unsubstituted or substituted by one or more substituents, which substituents are selected from the group consisting of alkyl, alkenyl, aryl, heteroaryl, heterocyclyl, arylalkyl, heteroarylalkyl, and heterocyclylalkyl.
The term xe2x80x9chaloalkylxe2x80x9d is inclusive of groups that are substituted by one or more halogen atoms, including perfluorinated groups. This is also true of groups that include the prefix xe2x80x9chalo-xe2x80x9d. Examples of suitable haloalkyl groups are chloromethyl, trifluoromethyl, and the like.
The term xe2x80x9carylxe2x80x9d as used herein includes carbocyclic aromatic rings or ring systems. Examples of aryl groups include phenyl, naphthyl, biphenyl, fluorenyl and indenyl. The term xe2x80x9cheteroarylxe2x80x9d includes aromatic rings or ring systems that contain at least one ring hetero atom (e.g., O, S, N). Suitable heteroaryl groups include furyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, indolyl, isoindolyl, triazolyl, pyrrolyl, tetrazolyl, imidazolyl, pyrazolyl, oxazolyl, thiazolyl, benzofuranyl, benzothiophenyl, carbazolyl, benzoxazolyl, pyrimidinyl, quinoxalinyl, benzimidazolyl, benzothiazolyl, naphthyridinyl, isoxazolyl, isothiazolyl, quinazolinyl, purinyl, and so on.
xe2x80x9cHeterocyclylxe2x80x9d includes non-aromatic rings or ring systems that contain at least one ring hetero atom (e.g., O, S, N) and includes the fully saturated and partially unsaturated derivatives of any of the above mentioned heteroaryl groups. Exemplary heterocyclic groups include pyrrolidinyl, tetrahydrofuranyl, morpholinyl, thiomorpholinyl, piperidinyl, piperazinyl, thiazolidinyl, imidazolidinyl, isothiazolidinyl, and the like.
The aryl, heteroaryl, and heterocyclyl groups can be unsubstituted or substituted by one or more substituents independently selected from the group consisting of alkyl, alkoxy, alkylthio, haloalkyl, haloalkoxy, haloalkylthio, halogen, nitro, hydroxy, mercapto, cyano, carboxy, formyl, aryl, aryloxy, arylthio, arylalkoxy, arylalkylthio, heteroaryl, heteroaryloxy, heteroarylthio, heteroarylalkoxy, heteroarylalkylthio, amino, alkylamino, dialkylamino, heterocyclyl, heterocycloalkyl, alkylcarbonyl, alkenylcarbonyl, alkoxycarbonyl, haloalkylcarbonyl, haloalkoxycarbonyl, alkylthiocarbonyl, arylcarbonyl, heteroarylcarbonyl, aryloxycarbonyl, heteroaryloxycarbonyl, arylthiocarbonyl, heteroarylthiocarbonyl, alkanoyloxy, alkanoylthio, alkanoylamino, aroyloxy, aroylthio, aroylamino, alkylaminosulfonyl, alkylsulfonyl, arylsulfonyl, heteroarylsulfonyl, aryldiazinyl, alkylsulfonylamino, alkylenesulfonylamino, arylsulfonylamino, arylalkylsulfonylamino,heteroarylsulfonylamino, heteroalkylsulfonylamino, alkylcarbonylamino, alkenylcarbonylamino, arylcarbonylamino, arylalkylcarbonylamino, heteroarylcarbonylamino, heteroarylalkylcarbonylamino, alkylaminocarbonylamino, alkenylaminocarbonylamino, arylaminocarbonylamino, arylalkylaminocarbonyl, heteroarylaminocarbonylamino, herteroarylalkylaminocarbonylamino, but, in the case of heterocyclyl, alkylcarbonyl, alkenylcarbonyl, haloalkylcarbonyl, arylcarbonyl, heteroarylcarbonyl, alkylthiocarbonyl, arylthiocarbonyl, heteroarylcarbonyl, alkylaminosulfonyl, alkylsulfonyl, arylsulfonyl, and heteroarylsulfonyl are not permitted. If any other groups are identified as being xe2x80x9csubstitutedxe2x80x9d or xe2x80x9coptionally substitutedxe2x80x9d, then those groups can also be substituted by one or more of the above enumerated substituents.
Certain substituents are generally preferred. For example, preferred heteroaryl groups include 2-pyridine, 3-pyridine, 4-pyridine, 2-pyrimidine, and 5-pyrimidine. Preferably no R substituents are present (i.e., n is 0). Preferred R2 groups include hydrogen, alkyl groups having 1 to 4 carbon atoms (i.e., methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and cyclopropylmethyl), methoxyethyl, and ethoxymethyl. One or more of these preferred substituents, if present, can be present in the compounds of the invention in any combination.
The invention is inclusive of the compounds described herein in any of their pharmaceutically acceptable forms, including isomers (e.g., diastereomers and enantiomers), salts, solvates, polymorphs, and the like. In particular, if a compound is optically active, the invention specifically includes each of the compound""s enantiomers as well as racemic mixtures of the enantiomers.
Pharmaceutical Compositions and Biological Activity
Pharmaceutical compositions of the invention contain a therapeutically effective amount of a compound of the invention as described above in combination with a pharmaceutically acceptable carrier.
The term xe2x80x9ca therapeutically effective amountxe2x80x9d means an amount of the compound sufficient to induce a therapeutic effect, such as cytokine induction, antitumor activity, and/or antiviral activity. Although the exact amount of active compound used in a pharmaceutical composition of the invention will vary according to factors known to those of skill in the art, such as the physical and chemical nature of the compound, the nature of the carrier, and the intended dosing regimen, it is anticipated that the compositions of the invention will contain sufficient active ingredient to provide a dose of about 100 ng/kg to about 50 mg/kg, preferably about 10 xcexcg/kg to about 5 mg/kg, of the compound to the subject. Any of the conventional dosage forms may be used, such as tablets, lozenges, parenteral formulations, syrups, creams, ointments, aerosol formulations, transdermal patches, transmucosal patches and the like.
The compounds of the invention can be administered as the single therapeutic agent in the treatment regimen, or the compounds of the invention may be administered in combination with one another or with other active agents, including additional immune response modifiers, antivirals, antibiotics, etc.
The compounds of the invention have been shown to induce the production of certain cytokines in experiments performed according to the tests set forth below. These results indicate that the compounds are useful as immune response modifiers that can modulate the immune response in a number of different ways, rendering them useful in the treatment of a variety of disorders.
Cytokines whose production may be induced by the administration of compounds according to the invention generally include interferon-xcex1 (IFN-xcex1) and/or tumor necrosis factor-xcex1 (TNF-xcex1) as well as certain interleukins (IL). Cytokines whose biosynthesis may be induced by compounds of the invention include IFN-xcex1, TNF-xcex1, IL-1, IL-6, IL-10 and IL-12, and a variety of other cytokines. Among other effects, these and other cytokines can inhibit virus production and tumor cell growth, making the compounds useful in the treatment of viral diseases and tumors. Accordingly, the invention provides a method of inducing cytokine biosynthesis in an animal comprising administering an effective amount of a compound or composition of the invention to the animal.
Certain compounds of the invention have been found to preferentially induce the expression of IFN-xcex1 in a population of hematopoietic cells such as PBMCs (peripheral blood mononuclear cells) containing pDC2 cells (precursor dendritic cell-type 2) without concomitant production of significant levels of inflammatory cytokines.
In addition to the ability to induce the production of cytokines, the compounds of the invention affect other aspects of the innate immune response. For example, natural killer cell activity may be stimulated, an effect that may be due to cytokine induction. The compounds may also activate macrophages, which in turn stimulates secretion of nitric oxide and the production of additional cytokines. Further, the compounds may cause proliferation and differentiation of B-lymphocytes.
Compounds of the invention also have an effect on the acquired immune response. For example, although there is not believed to be any direct effect on T cells or direct induction of T cell cytokines, the production of the T helper type 1 (Th1) cytokine IFN-xcex3 is induced indirectly and the production of the T helper type 2 (Th2) cytokines IL-4, IL-5 and IL-13 are inhibited upon administration of the compounds. This activity means that the compounds are useful in the treatment of diseases where upregulation of the Th1 response and/or downregulation of the Th2 response is desired. In view of the ability of compounds of the invention to inhibit the Th2 immune response, the compounds are expected to be useful in the treatment of atopic diseases, e.g., atopic dermatitis, asthma, allergy, allergic rhinitis; systemic lupus erythematosis; as a vaccine adjuvant for cell mediated immunity; and possibly as a treatment for recurrent fungal diseases and chlamydia.
The immune response modifying effects of the compounds make them useful in the treatment of a wide variety of conditions. Because of their ability to induce the production of cytokines such as IFN-xcex1 and/or TNF-xcex1, the compounds are particularly useful in the treatment of viral diseases and tumors. This immunomodulating activity suggests that compounds of the invention are useful in treating diseases such as, but not limited to, viral diseases including genital warts; common warts; plantar warts; Hepatitis B; Hepatitis C; Herpes Simplex Virus Type I and Type II; molluscum contagiosum; variola, particularly variola major; rhinovirus; adenovirus; influenza; para-influenza; HIV; CMV; VZV; intraepithelial neoplasias such as cervical intraepithelial neoplasia; human papillomavirus (HPV) and associated neoplasias; fungal diseases, e.g. candida, aspergillus, and cryptococcal meningitis; neoplastic diseases, e.g., basal cell carcinoma, hairy cell leukemia, Kaposi""s sarcoma, renal cell carcinoma, squamous cell carcinoma, myelogenous leukemia, multiple myeloma, melanoma, non-Hodgkin""s lymphoma, cutaneous T-cell lymphoma, and other cancers; parasitic diseases, e.g. pneumocystis carnii, cryptosporidiosis, histoplasmosis, toxoplasmosis, trypanosome infection, and leishmaniasis; and bacterial infections, e.g., tuberculosis, and mycobacterium avium. Additional diseases or conditions that can be treated using the compounds of the invention include actinic keratosis; eczema; eosinophilia; essential thrombocythaemia; leprosy; multiple sclerosis; Ommen""s syndrome; discoid lupus; Bowen""s disease; Bowenoid papulosis; alopecia areata; the inhibition of keloid formation after surgery and other types of post-surgical scars. In addition, these compounds could enhance or stimulate the healing of wounds, including chronic wounds. The compounds may be useful for treating the opportunistic infections and tumors that occur after suppression of cell mediated immunity in, for example, transplant patients, cancer patients and HIV patients.
An amount of a compound effective to induce cytokine biosynthesis is an amount sufficient to cause one or more cell types, such as monocytes, macrophages, dendritic cells and B-cells to produce an amount of one or more cytokines such as, for example, IFN-xcex1, TNF-xcex1, IL-1, IL-6, IL-10 and IL-12 that is increased over the background level of such cytokines. The precise amount will vary according to factors known in the art but is expected to be a dose of about 100 ng/kg to about 50 mg/kg, preferably about 10 xcexcg/kg to about 5 mg/kg. The invention also provides a method of treating a viral infection in an animal and a method of treating a neoplastic disease in an animal comprising administering an effective amount of a compound or composition of the invention to the animal. An amount effective to treat or inhibit a viral infection is an amount that will cause a reduction in one or more of the manifestations of viral infection, such as viral lesions, viral load, rate of virus production, and mortality as compared to untreated control animals. The precise amount will vary according to factors known in the art but is expected to be a dose of about 100 ng/kg to about 50 mg/kg, preferably about 10 xcexcg/kg to about 5 mg/kg. An amount of a compound effective to treat a neoplastic condition is an amount that will cause a reduction in tumor size or in the number of tumor foci. Again, the precise amount will vary according to factors known in the art but is expected to be a dose of about 100 ng/kg to about 50 mg/kg, preferably about 10 xcexcg/kg to about 5 mg/kg.
The invention is further described by the following examples, which are provided for illustration only and are not intended to be limiting in any way.
In the examples below some of the compounds were purified using semi-preparative HPLC. Two different methods were used and they are described below. Both methods used a A-100 Gilson-6 equipped with 900 Series Intelligent Interface. The semi-prep HPLC fractions were analyzed by LC-APCI/MS and the appropriate fractions were combined and lyophilized to provide the trifluoroacetate salt of the desired compound.
Method A
Column: column Microsorb C18, 21.4xc3x97250 mm, 8 micron particle size, 60 xc3x85 pore; flow rate: 10 mL/min.; gradient elution from 2-95% B in 25 min., hold at 95% B for 5 min., where A=0.1% trifluoroacetic acid/water and B=0.1% trifluoroacetic acid/acetonitrile; peak detection at 254 nm for triggering fraction collection.
Method B
Column: Phenomenex Capcell PakC18, 35xc3x9720 mm, 5 micron particle size; flow rate: 20 mL/min.; gradient elution from 5-95% B in 10 min., hold at 95% B for 2 min., where A=0.1% trifluoroacetic acid/water and B=0.1% trifluoroacetic acid/acetonitrile; peak detection at 254 nm for triggering fraction collection.